The bases for the decreased pain threshold and pain tolerance that is characteristic of people with fibromyalgia remain to be clarified. In addition to biological variables, such as gender, central sensitization, "wind-up" (abnormal temporal summation of pain), and central dysregulation of several axes of the stress response, cognitive, behavioral, emotional, environmental, and cultural variables appear to contribute importantly to the chronic pain experience and associated symptomatology in this disorder. A common denominator linking both biological and psychosocial contributors in this regard may be psychologic distress. The applicant's preliminary data are consistent with the hypothesis that psychological distress lowers pain threshold and, therefore, contributes to widespread allodynia and hyperalgesia in fibromyalgia. The immediate objective of this proposal is to use established databases from a cohort of patients with fibromyalgia and other rheumatologic conditions to define some of the individual differences that underlie the development and perpetuation of chronic widespread pain. This will be accomplished through the following Specific Aims: Aim 1, to determine the association of psychological distress with pain threshold and tolerance using thermal and ischemic pain techniques; Aim 2, to determine whether helplessness, optimism, and pessimism are associated with defined patterns of self-reported pain, pressure pain threshold and distress in patients with fibromyalgia and other rheumatologic disorders; and Aim 3, to determine whether our preliminary data showing an inverse relationship of distress and pressure pain threshold in fibromyalgia and other rheumatic disease patients receiving care in an academic medical center also obtain for patients in the community. Aim 3 will allow us to determine the generalizability of our preliminary data through comparisons of the UNC Arthritis Clinic Database, which consists of information on consecutive patients obtained from completion of a self-report questionnaire, Activities and Lifestyle Index and pressure pain threshold by algometry at 4 fibromyalgia tender points and the NC Rheumatologists Database also based on the Activities and Lifestyle Index completed by patients of rheumatologists in private practice in North Carolina; in addition, cross-sectional - data concerning the relationship of psychological distress and pressure pain threshold by algometry will be obtained in a subset of patients with fibromyalgia and other diagnoses under the care of NC rheumatologists.